1. Field of the Invention
This invention relates to a method of preparing powdered alloys such as cemented carbides, cermets, ceramics and ferrous alloys by sintering and more particularly, it is concerned with a novel method of sintering powdered alloys, whereby it is made possible to produce high quality alloys that cannot be obtained by the prior art vacuum sintering method or gas atmosphere sintering method.
2. Description of the Prior Art
Up to the present time, TiC-containing WC base cemented carbides and TiC base cermets have been subjected to reduction by sintering in vacuum, H.sub.2 atmosphere under reduced pressure or CO atmosphere under reduced pressure. According to this method, however, the reduction cannot completely be carried out and a large quantity of oxygen remains in the alloy, thus degrading the sintering property. N-containing TiC base cermets and N-containing WC base cemented carbides have generally been sintered in N.sub.2 atmosphere under reduced pressure, but in this case, a number of cavities are formed in the alloy even if denitrification is prevented and accordingly, a compact alloy cannot be obtained.